When everything is coming your way you re obviously in the wrong lane OK so what s the speed of dark OCNG 251 Oceanography Tuesday Sept 30th 2008 Part 2 i Earth Heat Balance ii The Ocean Atmosphere coupling Who laughs last thinks slowest Review Figure from The Earth Radiation Budget Experiment ERBE Global Radiation Balance Equation Temperatures Deficit Surplus Our Atmosphere Extremely dynamic system driven by solar heating Composed of different air packets at different temperatures Warm gas expands lowering density and leading to pressure differences wind Sea Breeze Warm gas expands lowering density and leading to pressure differences Our Atmosphere Warm gas expands lowering density and leading to pressure differences Atmospheric Regional Transport The Central American Smoke Event of May 1998 Combustion and Global Transport Earth s energy budget is initially at disequilibrium Since we are dealing with ultra fine particles we are bound to see some wide geographical distribution Earth s Heat Budget Qs Qb Qs Qb Qs Qb Amount of solar radiation received annually at the Earth s surface Hadley et al 2007 J Geophys Geophys Res Res Vol Vol 112 North American emissions of BC 41 5 G Month Input transport 32 G Month 75 originates from Asia The Atmosphere starts Moving Simplified Global Circulation Patterns Equator Low pressure zone N Coriolis Acceleration on Earth At the North and South Poles is vertical to the surface and anywhere else it is slanted to the surface with an angle equal to the local colatitude 90 the latitude angle angle Poles High pressure zones Simple circulation cell in each hemisphere with Surface winds directed towards the Equator Upper level winds directed towards the poles That s it That s it S The local angular velocity component vertical to the surface is sin sin It describes the rotation of the local surface around the radius connecting it to the center of the Earth The Coriolis Effect The Earth rotates upon its axis The vertical angular velocity increases from 0 km h at the equator to a maximum value at the poles N Geostrophic Flow with Friction S http www classzone com books earth science terc content visualizations es1904 es1904page01 cfm chapter no 19 Atmospheric Wind patterns Atmospheric Wind patterns High Low Pressure systems Heat capacity High Low Pressure systems Heat capacity July January Atmospheric Wind patterns January Global Circulation Patterns 1 Atmosphere N Atmospheric circulation results from 1 Earth s rotation and 2 differential heating at surface and in atmosphere this produces prevailing winds and latitudinal belts of high low pressure Earth is essentially divided into two atmospheric sections red line So is this it Westerlies Easterlies Easterlies Westerlies S High Low Pressure systems Wind generation Global Circulation Patterns 2 Oceans Global Circulation Patterns 3 Atmosphere Ocean coupling Low latitudes Oceans High latitudes Atmosphere Surface oceanic circulation results from 1 Prevailing winds differential heating at surface and in atmosphere and 2 Earth s rotation this produces prevailing currents and heat transfer High Heat Capacity Delayed Response Time Evaporation is the largest transfer flux of energy heat from the ocean to the atmosphere The Gulf Stream Atmosphere Ocean coupling Atmosphere Transfer of moisture to the atmosphere heat released in higher latitudes as water condenses Atmosphere Ocean coupling Atmosphere Transfer of moisture to the atmosphere Hurricanes www weather com Hurricane formation Hurricanes are commonly formed by easterly waves In the Atlantic the waves are kinks in the African Easterly Jet a strong wind that blows over the Atlantic from the West African coast The easterly waves trigger strong thunderstorms that move westward Over the warm waters of the Atlantic the thunderstorms embedded in the easterly wave can grow into a hurricane under the right conditions Rule of thumb If hurricanes form before 40 W then get tend to miss the U S A If hurricanes form beyond 70 W then there is a greater chance that they ll hit the U S A Atmosphere Ocean coupling Atmosphere Transfer of moisture to the atmosphere Hurricanes Climate of un certainty Seasonal Activity Validity Validity vs vs Value Value of Forecasts Gustav Gustav s forecast was spot on on 3 4 days in advance Did it help that it wasn wasn t as destructive destructive as announced Climate of un certainty Forecasting hurricanes Based on a range of models it is likely that future tropical cyclones typhoons and hurricanes will become more intense with larger peak wind speeds and more heavy precipitation associated with ongoing increases of tropical SSTs IGPCC Hurricane incidence Intensity El Ni o inverse Storms in western Africa direct SST Atlantic direct Univ Univ of Colorado 2005 Next Class Physical properties of sea water Density structure of Ocean